Add missing dep "react-addons-test-utils"

Author: aputinski

package.json

@@ -41,8 +41,7 @@
     "minimist": "1.2.0",
     "mocha": "3.0.2",
     "react": "15.3.1",
-    "react": "15.3.1",
-    "react": "15.3.1",
+    "react-addons-test-utils": "^15.3.1",
     "sinon": "1.17.5",
     "standard": "8.0.0-beta.5",
     "webpack": "1.13.2",